The main objective of the SCOR-A is to study the early natural history of atherosclerosis and hypertension. A major effort concerns the distribution and prevalence of risk factor variables in children, from infancy through young adulthood, in a semi-rural and biracial community - the Bogalusa Heart Study. Research concerns height-weight, skinfold, blood pressure, lipids and lipoproteins, smoking, and blood glucose. The interrelationship of these variables is being studied along with determinants of high and low levels of blood pressure and lipids. The changes over time of these variables are also being observed over the duration of the study. Dietary studies obtained on a sample of children show little or no correlation of diet with serum lipids or blood pressure, although children with lowest levels of serum cholesterol consume less fat and saturated fatty acids. A high degree of correlation occurs in the anthropometric, blood pressure, and lipid measurements from one year to the next indicating a significant "tracking" occurs, a persistence of children in their respective ranks. The data also indicate that essential hypertension likely begins in early childhood. Further, serum cholesterol levels of two-year-old infants are already similar to young adults. The experimental research includes nutritional models in nonhuman primates to simulate hyperlipoproteinemias. An interesting synergistic effect between sucrose and exogenous cholesterol has been found in both squirrel and spider monkeys. Other studies of the chemistry of atherosclerotic lesions in the arterial wall show an interaction and complexing of glycosaminoglycans with serum lipoproteins. Selective extractions of fibrous plaque lesions further indicate a specific interaction of complexes within the aorta with collagen and elastin.